Aircraft air scoop systems with passive pneumatic actuators

ABSTRACT

Aircraft and air scoop systems are provided. An aircraft includes an interior compartment, an outer skin, an air scoop, a movable element, and a passive pneumatic actuator. The interior compartment encloses a substantially constant interior air mass at a cabin pressure during flight and the outer skin at least partially defines a ventilated cavity. The air scoop is disposed on the outer skin and communicates air between the ventilated cavity and an external environment in which the aircraft is located. The movable element is movable between an open position and a closed position over the air scoop to define an air flow area through the air scoop. The passive pneumatic actuator is operatively coupled with the movable element and moves the movable element towards the closed position in response to an increasing altitude of the aircraft based on a differential pressure between the interior air mass and the external environment.

CROSS-REFERENCE TO RELATED APPLICATION

This Application is a Continuation of U.S. patent application Ser. No.14/314,170 filed Jun. 25, 2014, which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

The technical field relates generally to air scoop systems for aircraft,and more particularly relates to air scoop systems with passivepneumatic actuators for passively modulating openings.

BACKGROUND

A conventional passenger aircraft includes one or more ventilatedcavities that are not pressurized during flight. One typical ventilatedcavity resides within the wing-to-body fairing that forms a blendedaerodynamic surface between the fuselage and wing. These wing-to-bodyfairings are typically ventilated with air scoops or air inlets toremove air that could possibly contain fuel vapors. Another typicalventilated cavity is an enclosure for a heat exchanger of environmentalcontrol systems on the aircraft.

As the speed of the aircraft increases, the air flow through theseventilated cavities increases with a fixed area air scoop. Thisincreased air flow causes excess noise in the cabin of the aircraft andcan increase the aerodynamic drag on the aircraft. One solution fordecreasing this excess noise and drag is to modulate the area of the airscoop. Such modulation is typically accomplished with use of electronicactuators and sensors to actively manage the area of the air scoop.These actively managed air scoops have the disadvantage of requiringadditional electronic components and adding complexity to the aircraft.

As such, it is desirable to provide air scoop systems with modulatingareas that have reduced management complexity. In addition, otherdesirable features and characteristics will become apparent from thesubsequent summary and detailed description, and the appended claims,taken in conjunction with the accompanying drawings and this background.

SUMMARY OF EMBODIMENTS

Various non-limiting embodiments of aircraft and air scoop systems foraircraft are disclosed herein.

In a first non-limiting embodiment, an aircraft includes, but is notlimited to, an interior compartment, an outer skin, an air scoop, amovable element, and a passive pneumatic actuator. The interiorcompartment encloses a substantially constant interior air mass at acabin pressure during flight and the outer skin at least partiallydefines a ventilated cavity. The air scoop is disposed on the outer skinand communicates air between the ventilated cavity and an externalenvironment in which the aircraft is located. The movable element ismovable between an open position and a closed position over the airscoop to define an air flow area through the air scoop. The passivepneumatic actuator is operatively coupled with the movable element andmoves the movable element towards the closed position in response to anincreasing altitude of the aircraft based on a differential pressurebetween the interior air mass and the external environment.

In a second non-limiting embodiment, an air scoop system includes, butis not limited to, an air scoop, a movable element, and a passivepneumatic actuator. The air scoop is configured to be disposed on anouter skin of the aircraft and is configured to communicate air betweena ventilated cavity and an external environment in which the aircraft islocated. The movable element is movable between an open position and aclosed position over the air scoop to define an air flow area throughthe air scoop. The passive pneumatic actuator is operatively coupledwith the movable element and is configured to move the movable elementtowards the closed position in response to an increasing altitude of theaircraft based on a differential pressure between the externalenvironment and a substantially constant interior air mass enclosed byan interior compartment of the aircraft at a cabin pressure duringflight of the aircraft.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the present invention will be readily appreciated, as thesame becomes better understood by reference to the following detaileddescription when considered in connection with the accompanying drawingswherein:

FIG. 1 is a side view illustrating a non-limiting embodiment of anaircraft in accordance with the teachings of the present disclosure;

FIGS. 2A and 2B are cross-sectional views illustrating a non-limitingembodiment of the air scoop system of FIG. 1 in accordance with theteachings of the present disclosure;

FIG. 3 is a cross-sectional view illustrating a non-limiting embodimentof the air scoop system of FIG. 1 in accordance with the teachings ofthe present disclosure;

FIGS. 4 and 5 are cross-sectional views illustrating non-limitingembodiments of passive pneumatic actuators of the air scoop system ofFIG. 1 in accordance with the teachings of the present disclosure; and

FIGS. 6A and 6B are cross-sectional views illustrating a non-limitingembodiment of the air scoop system of FIG. 1 in accordance with theteachings of the present disclosure.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the invention or the application and uses of theinvention. Furthermore, there is no intention to be bound by any theorypresented in the preceding background or the following detaileddescription.

Various non-limiting embodiments of aircraft and air scoop systems aredisclosed herein. A greater understanding of the aircraft and air scoopsystems may be obtained through a review of the illustrationsaccompanying this application together with a review of the detaileddescription that follows.

FIG. 1 is a side view illustrating a non-limiting embodiment of anaircraft 100 in accordance with the teachings of the present disclosure.Aircraft 100 includes an outer skin 108, an interior compartment 110, awing-to-body fairing 112, a fairing cavity 115, an environmental controlsystem (ECS) compartment 114, and air scoop systems 118. Outer skin 108defines an outer periphery of aircraft 100 that is wetted by externalairflow as the aircraft flies through the air, including portions of thefuselage skin 109, wing, tail and engine and their associatedaerodynamic fairings. This embodiment includes portions of the fuselageskin, the wing-to-body fairing 112, and the ECS compartment 114. Thewing-to-body fairing 112 is a subset of the outer skin 108.

Interior compartment 110 is a pressure vessel that includes the cabinand cockpit of aircraft 100. Various pressurization components (notillustrated) maintain interior compartment 110 at a cabin pressure whenaircraft 100 is in flight, as will be appreciated by those with skill inthe art. An interior air mass enclosed by interior compartment 110typically remains at a higher pressure than the external environment 119to maintain passenger comfort.

Fairing cavity 115 and ECS compartment 114 are ventilated cavities thatare not pressurized during flight of aircraft 100 and have internalpressures similar in magnitude to the external environment 119.Wing-to-body fairing 112 is ventilated according to Federal AviationAdministration requirements based on removing potential fuel vapor fromfairing cavity 115. ECS compartment 114 is ventilated to provide coolair to a heat exchanger component of air conditioning portions of theECS.

Air scoop systems 118 are disposed on outer skin 108 and are configuredto communicate air between ventilated cavities (e.g., fairing cavity 115and ECS compartment 114) and an external environment 119 in whichaircraft 100 is located. Air scoop systems 118 may include air inlets orair outlets without departing from the scope of the present disclosure.In some embodiments, air scoop systems 118 include air inlets and theventilated cavities include conventional air outlets.

With further reference to FIGS. 2A and 2B, cross-sectional viewsillustrate a non-limiting embodiment of air scoop system 118 inaccordance with the teachings of the present disclosure. Each air scoopsystem 118 includes an air scoop 120, a movable element 122, a passivepneumatic actuator 124, a pressure actuated valve 126, an air pressuresupply line 133, and two resilient members 128. Air scoop system 118 ismovable between an open position and a closed position based on thealtitude of aircraft 100, as will be described below. In the openposition, an air flow area through which air can flow through air scoopsystem 118 and the ventilated cavity is maximized. The maximized airflow area is preselected to provide an air flow based on a low speedoperation of aircraft 100, such as during takeoff/landing and flightbelow 10,000 feet. In the closed position, the air flow area throughwhich air can flow through air scoop system 118 and the ventilatedcavity is minimized. The minimized air flow area is typicallypreselected to provide an air flow based on a high speed operation ofaircraft 100, such as when aircraft 100 is at cruising speed.

Air scoop 120 is an aperture or opening in outer skin 108. In theexample provided, air scoop 120 includes a fixed member 130 extendinginto the ventilated cavity from outer skin 108. Fixed member 130provides a counter-acting force to passive pneumatic actuator 124 andresilient members 128, as will be described below. Air scoop 120 mayhave various shapes to reduce wind noise within or drag on aircraft 100,as will be appreciated by those with skill in the art.

Movable element 122 is movable between an open position and a closedposition over air scoop 120 to define an air flow area through air scoop120. The open and closed positions of movable element 122 define theopen and closed positions of air scoop system 118, as will beappreciated by those with skill in the art. By varying the air flowarea, the air flow through the ventilated cavity may be modulated toreduce air flow at higher altitudes where aircraft 100 is typically at acruising speed. In the example provided, movable element 122 is anarticulating ramp that is secured to air scoop 120 or outer skin 108with a hinge 132.

Passive pneumatic actuator 124 is operatively coupled with movableelement 122. Passive pneumatic actuator 124 is further configured tomove movable element 122 towards the closed position and in response toan increasing altitude of aircraft 100 based on a differential pressurebetween the interior air mass in interior compartment 110 and externalenvironment 119. As will be appreciated by those with skill in the art,as altitude of aircraft 100 increases, atmospheric pressure in externalenvironment 119 decreases. The forces provided by passive pneumaticactuator 124 and resilient member 128 may vary and be optimized forparticular applications without departing from the scope of the presentdisclosure.

In the example provided, passive pneumatic actuator 124 is an airbladder that rotates movable element 122 about hinge 132. In someembodiments, passive pneumatic actuator 124 is a bellows system, apneumatic piston, or any other device that may be used to passivelyactuate movable element 122 based on the differential pressure. Passivepneumatic actuator 124 is configured to put movable element 122 in theclosed position when aircraft 100 is at a cruise altitude. As will beappreciated by those with skill in the art, aircraft 100 is generallytraveling at a cruising speed when at cruise altitude. At cruisingspeed, the air flow area of air scoop system 118 when movable element122 is in the closed position is sufficient to ventilate the ventilatedcavity.

The interior air mass of interior compartment 110 is much larger thanthe volume of air used to actuate passive pneumatic actuator 124.Accordingly, the air pressure of the interior air mass in interiorcompartment 110 may be considered to be substantially constantthroughout the movable range of passive pneumatic actuator 124 andmovable element 122.

Pressure actuated valve 126 is operatively coupled between the interiorair mass of interior compartment 110 and passive pneumatic actuator 124.Pressure actuated valve 126 restricts air flow from interior compartment110 to passive pneumatic actuator 124 when the differential pressurebetween interior compartment 110 and external environment 119 is below athreshold value. By way of example, pressure actuated valve 126 may beselected to open at a specific p. s. i. d. and keep air scoop system 118in the open position at low altitudes and speeds. Passive pneumaticactuator 124 may also contain a small exit port 131 to allow pressurizedair to slowly escape so that pressurized air is not trapped in thepassive pneumatic actuator 124 when pressure actuated valve 126 isclosed. In some embodiments, pressure actuated valve 126 is omitted, andthe interior air mass is in direct fluid communication with movableelement 130.

In the example provided, resilient members 128 are coil springs intension between fixed member 130 and movable element 122. In otherembodiments, other type of resilient members may be utilized. Tensionwithin resilient members 128 pulls movable element 122 toward fixedmember 130 and away from outer skin 108 to urge air scoop system 118into the open position. Passive pneumatic actuator 124, resilientmembers 128, and pressure actuated valve 126 cooperate to positionmovable element 122 in the open position when the aircraft is below athreshold altitude to maximize the air flow area. As will be appreciatedby those with skill in the art, at low altitudes aircraft 100 isgenerally traveling at low air speeds and a maximized air flow area isdesirable to provide sufficient ventilation of fairing cavity 115 or ECScompartment 114. It should be appreciated that any number of resilientmembers 128 may be utilized in any given implementation withoutdeparting from the scope of the present disclosure.

With further reference to FIG. 3, a cross-sectional view illustrates anon-limiting embodiment of an air scoop system 118′ in accordance withthe teachings of the present disclosure. Air scoop system 118′ issimilar to air scoop system 118, where like numbers refer to likecomponents. Air scoop system 118′, however, includes movable element122′, passive pneumatic actuator 124′, resilient member 128′, andadditional fixed members 130′.

Movable element 122′ is a guillotine member that translates across airscoop 120 to vary an air flow area of air scoop system 118′. It shouldbe appreciated that movable element 122′ may translate in any directionacross air scoop 120 without departing from the scope of the presentdisclosure. Movable element 122′ is in sliding engagement with an innersurface of outer skin 108. Passive pneumatic actuator 124′ may be anysuitable system, such as a pneumatic piston and cylinder system, abellows, or a bladder. A first side 140 of pneumatic actuator 124′ is inpneumatic communication with interior compartment 110 through pressureactuated valve 126 and air pressure supply line 133. A second side 142of pneumatic actuator 124′ is in pneumatic communication with externalenvironment 119. The pressure differential between interior compartment110 and external environment 119 provides a net force across the pistonof pneumatic actuator 124′ to translate movable element 122′.

Fixed members 130′ are similar to fixed member 130. Fixed members 130′,however, are secured to outer skin 108 or other structural components ofaircraft 100 and are separated from air scoop 120. In the exampleprovided, fixed members 130′ are disposed downstream of air scoop 120with respect to air flow through fairing cavity 115 or ECS compartment114. Resilient member 128′ is similar to resilient member 128, but isdisposed between fixed member 130′ and movable element 122′.

Referring now to FIG. 4, a cross-sectional view illustrates anon-limiting embodiment of a passive pneumatic actuator 200 inaccordance with teachings of the present disclosure. Passive pneumaticactuator 200 may be utilized in air scoop system 118 or 118′ in place ofor in addition to passive pneumatic actuator 124 and/or 124′. Passivepneumatic actuator 200 is a cylindrical “oil can” design with adiaphragm 210 separating an enclosed cavity 212 from the fairing cavity115. Actuation rod 262 is in communication with movable element 122. Asthe differential pressure between the enclosed cavity 212 and fairingcavity 115 varies, diaphragm 210 flexes and adjusts a force applied tomovable element 122 through actuation rod 262 to vary the air flow area,as will be appreciated by those with skill in the art. Resilient member254 is compressed between the outer surface of the diaphragm 210 andfixed member 130 to bias actuation rod 262 and urge movable element 122towards the open position. Check valve 127 allows re-pressurization ofenclosed cavity 212 when pressure in fairing cavity 115 is higher thanthe pressure in enclosed cavity 212.

Referring now to FIG. 5, a cross-sectional view illustrates anon-limiting embodiment of a passive pneumatic actuator 250 inaccordance with teachings of the present disclosure. Passive pneumaticactuator 250 may be utilized in air scoop system 118 or 118′ in place ofor in addition to passive pneumatic actuator 124 and/or 124′. Passivepneumatic actuator 250 is a pneumatic piston design that is similar topassive pneumatic actuator 124′, where like numbers refer to likecomponents. Passive pneumatic actuator 250, however, includes a bladder252 and a resilient member 254.

Bladder 252 is in pneumatic communication with pressure actuated checkvalve 127 and is disposed in first cavity 140 to a first side of apiston 260. An actuation rod 262 extends from a second side of piston260 and couples with movable element 122 or 122′. As the differentialpressure between interior compartment 110 and external environment 119varies, bladder 252 expands and adjusts a force applied to movableelement 122 to vary the air flow area, as will be appreciated by thosewith skill in the art. Resilient member 254 is compressed between thesecond side of piston 260 and fixed member 130 to bias piston 260 andurge movable element 122 towards the open position.

Referring now to FIGS. 6A and 6B, cross-sectional views illustrate anon-limiting embodiment of an air scoop system 300 in accordance withthe teachings of the present disclosure. Air scoop system 300 is similarto air scoop system 118 and air scoop system 118′, where like numbersrefer to like components. Air scoop system 300, however, includespassive pneumatic actuator 310 and movable element 312.

Passive pneumatic actuator 310 is an air bellows device that expands orcontracts based on a differential pressure between an interior and anexterior of the bellows device. The interior of the air bellows deviceis in pneumatic communication with interior compartment 110 throughpressure actuated valve 126 and pressure supply line 133. The exteriorof the air bellows device is exposed to fairing cavity 115. In someembodiments, passive pneumatic actuator 310 is a bellows device with asealed volume of air, or a near vacuum volume of air, that omitspressure actuated valve 126. The delta pressure between the internalvolume of the bellows and the external environment 119 in suchembodiments causes the bellows to contract and urges movable element 312towards the open position at low altitudes of aircraft 100.

Movable element 312 is an articulating ramp similar to movable element122. Movable element 312, however, includes a first portion 316 and asecond portion 318 that define a groove 320. First and second portions316 and 318 include outer surfaces 322 that are substantially co-planarwith outer skin 108 when air scoop system 300 is in the closed position.Groove 320 between first portion 316 and second portion 318 defines aminimum air flow area for permitting air flow through the ventilatedcavity when air scoop system 300 is in the closed position.

While at least one exemplary embodiment has been presented in theforegoing detailed description of the invention, it should beappreciated that a vast number of variations exist. It should also beappreciated that the exemplary embodiment or exemplary embodiments areonly examples, and are not intended to limit the scope, applicability,or configuration of the invention in any way. Rather, the foregoingdetailed description will provide those skilled in the art with aconvenient road map for implementing an exemplary embodiment of theinvention. It being understood that various changes may be made in thefunction and arrangement of elements described in an exemplaryembodiment without departing from the scope of the invention as setforth in the appended claims.

What is claimed is:
 1. An aircraft, comprising: an interior compartmentconfigured to enclose a substantially constant interior air mass at acabin pressure during flight of the aircraft; an outer skin that atleast partially defines a ventilated cavity; an air scoop disposed onthe outer skin and configured to communicate air between the ventilatedcavity and an external environment in which the aircraft is located; amovable element movable between an open position and a closed positionover the air scoop to define an air flow area through the air scoop; anda passive pneumatic actuator comprising a first side in pneumaticcommunication with the interior compartment and a second side inpneumatic communication with the external environment, wherein thepassive pneumatic actuator is operatively coupled with the movableelement and is configured to move the movable element towards the closedposition in response to an increasing altitude of the aircraft based ona differential pressure between the interior air mass and the externalenvironment.
 2. The aircraft of claim 1, wherein the interiorcompartment at least partially defines a cabin and a cockpit of theaircraft.
 3. The aircraft of claim 1, further comprising a resilientmember biasing the movable element towards the open position.
 4. Theaircraft of claim 3, wherein the passive pneumatic actuator and theresilient member cooperate to position the movable element in the openposition when the aircraft is below a threshold altitude to maximize theair flow area.
 5. The aircraft of claim 1, wherein the passive pneumaticactuator is configured to position the movable element in the closedposition when the aircraft is at a cruise altitude to minimize the airflow area.
 6. The aircraft of claim 1, wherein the ventilated cavity isa wing-to-body fairing.
 7. The aircraft of claim 1, wherein theventilated cavity encloses components of an environmental controlsystem.
 8. The aircraft of claim 1, wherein the movable element is anarticulating ramp that is secured to the air scoop with a hinge, andwherein the passive pneumatic actuator is configured to rotate thearticulating ramp about the hinge.
 9. The aircraft of claim 1, whereinthe movable element is a guillotine member, and wherein the passivepneumatic actuator is configured to translate the guillotine memberacross the air scoop to vary the air flow area.
 10. The aircraft ofclaim 1, wherein the passive pneumatic actuator is one of an air bladderand an air bellows.
 11. The aircraft of claim 1, wherein the passivepneumatic actuator is a pneumatic piston.
 12. An air scoop system for anaircraft, the air scoop system comprising: an air scoop configured to bedisposed on an outer skin of the aircraft and configured to communicateair between a ventilated cavity and an external environment in which theaircraft is located; a movable element movable between an open positionand a closed position over the air scoop to define an air flow areathrough the air scoop; and a passive pneumatic actuator comprising afirst operable side and a second operable side, wherein the passivepneumatic actuator is operatively coupled with the movable element andconfigured to move the movable element towards the closed position inresponse to an increasing altitude of the aircraft based on adifferential pressure between the external environment and asubstantially constant interior air mass enclosed by an interiorcompartment of the aircraft at a cabin pressure during flight of theaircraft, and wherein the first operable side is in pneumaticcommunication with the interior compartment and the second operable sideis in pneumatic communication with the external environment.
 13. The airscoop system of claim 12, further comprising a resilient member biasingthe movable element towards the open position.
 14. The air scoop systemof claim 13, wherein the passive pneumatic actuator and the resilientmember cooperate to position the movable element in the open positionwhen the aircraft is below a threshold altitude to maximize the air flowarea.
 15. The air scoop system of claim 12, wherein the passivepneumatic actuator is configured to position the movable element in theclosed position when the aircraft is at a cruise altitude to minimizethe air flow area.
 16. The air scoop system of claim 12, wherein the airscoop system is configured to provide ventilation to one of awing-to-body fairing and a cavity that encloses components of anenvironmental control system.
 17. The air scoop system of claim 12,wherein the movable element is an articulating ramp that is secured tothe air scoop with a hinge, and wherein the passive pneumatic actuatoris configured to rotate the articulating ramp about the hinge.
 18. Theair scoop system of claim 12, wherein the movable element is aguillotine member, and wherein the passive pneumatic actuator isconfigured to translate the guillotine member across the air scoop tovary the air flow area.